IEC 61730 2 Edition 1 1 2012 11 INTERNATIONAL STANDARD NORME INTERNATIONALE Photovoltaic (PV) module safety qualification – Part 2 Requirements for testing Qualification pour la sûreté de fonctionneme[.]
General
Photovoltaic modules can be utilized in various applications, making it essential to assess the potential hazards linked to each application and to design the modules accordingly.
To ensure compliance with safety standards, it is essential to conduct relevant tests that verify adherence to the specific requirements of each application class This section outlines the various application classes and the construction qualities mandated for each.
Application classes for PV-modules are defined as follows:
Class A: General access, hazardous voltage, hazardous power applications
Modules designed for this application class can be utilized in systems exceeding 50 V DC or 240 W, particularly where general contact access is expected Those modules that have been certified for safety according to IEC 61730-1 and the relevant section of IEC 61730 are deemed to fulfill the safety class II requirements.
Class B: Restricted access, hazardous voltage, hazardous power
Modules designed for this application class are limited to systems that are safeguarded from public access through barriers such as fences and strategic location Those evaluated in this category offer protection through basic insulation and are deemed to fulfill the criteria for safety class 0.
Class C: Limited voltage, limited power applications
Modules rated for use in this application class are restricted to systems operating at less than
The modules operate at 50 V DC and 240 W, designed for general contact access They are qualified for safety according to IEC 61730-1 and the relevant section of IEC 61730, ensuring compliance with safety class III requirements.
NOTE Safety classes are defined within IEC 61140
General
The lifespan and safety of photovoltaic (PV) modules can be affected by various hazards To address these risks, specific test procedures and criteria are outlined The tests a module undergoes will vary based on its intended application, with minimum testing requirements detailed in Clause 5.
NOTE Module safety tests are labelled MST
Tables 1 to 6 detail the origins of the required tests, with the third column providing additional information on some tests The relevant test requirements are specified in the corresponding clauses.
The remaining tests are derived from or are identical to IEC 61215 and IEC 61646, with references to the pertinent clauses provided in the last two columns.
IEC 61215/IEC 61646-based tests were modified for IEC 61730-2 and are included in Clauses
Preconditioning tests
MST 51 Thermal cycling (TC50 or TC200) 10.11 10.11
General inspection
Electrical shock hazard tests
These tests evaluate the potential risk of shock or injury to personnel from contact with electrically energized components of a module, which may arise from design, construction, or environmental and operational faults.
Table 3 – Electrical shock hazard tests
MST 11 Accessibility test ANSI/UL 1703
MST 12 Cut susceptibility test (not required for glass surfaces) ANSI/UL 1703
(not required unless metal framed)
MST 14 Impulse voltage test IEC 60664-1
MST 17 Wet leakage current test 10.15 10.20
MST 42 Robustness of terminations test 10.14 10.14
* The pass/fail criteria differ from those given in IEC 61215 and IEC 61646.
Fire hazard tests
These tests assess the potential fire hazard due to the operation of a module or failure of its components
MST 21 Temperature test ANSI/UL 1703
MST 23 Fire test ANSI/UL 790
MST 25 Bypass diode thermal test 10.18 10.18
MST 26 Reverse current overload test ANSI/UL 1703
Mechanical stress tests
These tests are to minimise potential injury due to mechanical failure
MST 32 Module breakage test ANSI Z97.1
Component tests
MST 15 Partial discharge test IEC 60664-1
MST 33 Conduit bending ANSI/UL 514C
MST 44 Terminal box knock out test ANSI/UL 514C
5 Application classes and their necessary test procedures
The tests a module undergoes are determined by the application class outlined in IEC 61730-1, as detailed in Table 7 The sequence of these tests is specified in Figure 1.
Some tests shall be carried out as preconditioning tests
NOTE This test sequence has been designed so that IEC 61730-2 can be performed in conjunction with
IEC 61215 or IEC 61646 In this way, the environmental stress tests in IEC 61215 or IEC 61646 can serve as the preconditioning tests for IEC 61730-2
Table 7 – Required tests, depending on the application class
MST 51 Thermal cycling (T50 or T200) MST 52 Humidity freeze (10HF) MST 53 Damp heat (DH1000) MST 54 UV resistance pre-conditioning
MST 11 Accessibility test MST 12 Cut susceptibility test MST 13 Ground continuity test MST 14 Impulse voltage test MST 16 Dielectric withstand test MST 17 Wet leakage current test
X X X MST 42 Robustness of terminations test
MST 21 Temperature test MST 22 Hot spot test MST 23 Fire test MST 26 Reverse current overload test
MST 32 Module breakage test MST 34 Mechanical load test
MST 15 Partial discharge test MST 33 Conduit bending MST 44 Terminal box knockout test
- Test needs not be carried out
* Different test levels for application classes A and B
** Minimum fire resistance class C is necessary for building roof-mounted modules
For safety testing, six modules and one laminate module (without a frame) will be randomly selected from a production batch, following the IEC 60410 procedure These modules must be made from specified materials and components, adhering to relevant drawings and process sheets, and must have passed the manufacturer's standard inspection, quality control, and acceptance procedures Each module should be fully complete and include the manufacturer's instructions for handling, mounting, and connections, along with the maximum permissible system voltage.
When the modules to be tested are prototypes of a new design and not from production, this fact shall be noted in the test report (see Clause 7)
The test report will be prepared in accordance with ISO/IEC 17025, detailing all necessary information for interpretation as requested by the client It will include a title, the name and address of the test laboratory, unique identification for the report, and client details Additionally, it will describe the tested item, its condition, and the dates of receipt and testing The report will identify the test method used, reference any relevant sampling procedures, and note any deviations or additional information pertinent to the tests, including environmental conditions It will present measurements and results supported by appropriate visuals, state whether the impulse voltage test was conducted on a module or laminate, and provide an estimated uncertainty of the results The report will be signed by the responsible individual, include the date of issue, and clarify that results pertain only to the tested items, along with a statement regarding reproduction restrictions without laboratory approval.
A copy of this report shall be kept by the manufacturer for reference purposes
1 If the module is only used with frame and the frame is an essential part to fulfil the isolation requirement, the laminate can be replaced by a module
The modules will be organized into groups and undergo the safety tests outlined in Figure 1, following the specified sequence Selection of the modules will ensure compliance with the preconditioning tests detailed in section 4.2 Each box in Figure 1 corresponds to the relevant subclause in this section.
NOTE Spare modules may be included in the safety test program provided that they have been appropriately environmentally tested to meet the necessary prerequisites
Test procedures and criteria, including necessary initial and final measurements, are outlined in Clauses 10 and 11 Certain tests mirror those found in IEC 61215/IEC 61646 and are specified in Clause 4 It is essential for testers to adhere closely to the manufacturer's instructions regarding handling, mounting, and connections during these tests.
Wet leakage current MST 17 test
Robustness of terminations test MST 42
Impulse voltage test MST 14 MST 14
Accessibility test MST 11 test MST 15
Terminal box knock out test MST 44 MST 44
Conduit bending test MST 33 MST 33
Number of modules depends on the module size
Bypass diode thermal test MST 25 16
01 10.2 17 The numbers in each box are references to final measurements, that are to be performed after MST or MPT (if required) In this example:
01 = Module safety test MST 01 10.2 = Performance test (IEC 61215, IEC 61646)
Wet leakage current MST 17 test
Wet leakage current MST 17 test
Robustness of terminations test MST 42
Terminal box knock out test MST 44 MST 44
Conduit bending MST 33 test MST 33
Number of modules depends on the module size
UV pre-conditioning test MST 54
Bypass diode thermal test MST 25
01 17 The numbers in each box are references to final measurements, that are to be performed after MST or MPT (if required) In this example:
Wet leakage current MST 17 test
Indicates change from Edition 1 are near the red bar
The module product under evaluation shall be judged to have passed the safety qualification test, if the test samples meet all of the criteria of each individual test
If any module does not meet these test criteria, the module product under evaluation shall be deemed not to have met the safety test requirements
NOTE The nature of the failure will determine the extent of re-testing requirements
Visual inspection MST 01
To detect any visual defects in the module
This test is identical with 10.1 from IEC 61215/IEC 61646 with the additional inspection criteria of
– any other conditions which may affect safety;
– markings not consistent with Clause 11 of IEC 61730-1
Document and photograph any cracks, bubbles, or delaminations, as these issues may worsen and compromise module safety in future tests Minor visual conditions not classified as major defects are acceptable for safety test approval.
For safety test approval, major visual defects include: a) broken, cracked, or torn external surfaces; b) bent or misaligned external surfaces, such as superstrates, substrates, frames, and junction boxes that could compromise module safety; c) bubbles or delaminations creating a continuous path between any part of the electrical circuit and the module's edge, especially if they show significant growth during testing; d) signs of molten or burned encapsulant, back sheet, diode, or active PV components; e) loss of mechanical integrity that could jeopardize the installation and operation safety of the module; and f) markings that do not comply with Clause 12 of IEC 61730-1.
Accessibility test MST 11
To determine if uninsulated electrical connections represent a shock hazard to personnel
The apparatus is as follows: a) A cylindrical test fixture Type 11 according to Figure 7 of IEC 61032 b) An ohmmeter or continuity tester
To test the module, first, mount and wire it according to the manufacturer's instructions Next, connect an ohmmeter or continuity tester to the module's electric circuit and the test fixture Remove all accessible covers, plugs, and connections from the module Then, probe around all electrical connectors, plugs, junction boxes, and other areas where the module's electrical circuit is accessible Finally, monitor the ohmmeter or continuity tester to check for electrical contact between the test fixture and the module's circuitry.
At no time during the test shall there be less than 1 MΩ resistance between the test fixture and the module electric circuit
The probe must not touch any live electrical components during the test This procedure is conducted at both the start and end of the sequence, as illustrated in Figure 1, and can also be applied at any point in the test sequence if there is concern that active electrical circuits may have been exposed during previous tests.
Cut susceptibility test MST 12
The test, based on ANSI/UL 1703, evaluates the ability of the front and rear surfaces of polymeric material modules to endure routine handling during installation and maintenance, ensuring that personnel are not at risk of electric shock.
A test fixture as shown in Figure 2, designed to draw a defined shaped object, a 0,64 mm ±
0,05 mm thick carbon steel blade (for example the back of a hacksaw blade) over the surface of the module with an applied force of 8,9 N ± 0,5 N
To conduct the procedure, first, position the module horizontally with the front surface facing upward Next, place the test fixture on the surface for one minute before moving it across the module at a speed of (150 ± 30) mm/s.
Repeat the procedure five times in different directions c) Repeat a) and b) for the rear surface of the module
Repeat MST 01, MST 13, MST 16 and MST 17
The pass criteria stipulate that there must be no visible signs of cutting on the superstrate or substrate surfaces that would expose the module's active circuitry Additionally, MST 13, MST 16, and MST 17 are required to adhere to the same standards as those established for the initial measurements.
Test point carbon steel strip (i.e hacksaw blade)
A 150 mm from axis to center of weight
B 170 mm from axis to test point
C Test point – 0,64 mm thick steel strip
Q Total force exerted at test point Q: 8,9 N
Ground continuity test MST 13
To ensure proper grounding in a photovoltaic (PV) system, it is essential to verify the conductive path between all exposed conductive surfaces of the module This test is necessary only when the module includes exposed conductive components, such as a metal frame or a metallic junction box.
The setup includes a constant current supply that generates a current 2.5 times greater than the maximum over-current protection rating of the module being tested, as specified in MST 26, along with an appropriate voltmeter for measurement.
NOTE According to IEC 61730-1 the maximum over-current protection rating has to be provided by the manufacturer
To conduct the grounding test, first, select the manufacturer's designated grounding point and connect it to one terminal of the constant current supply Next, identify an adjacent exposed conductive component that is physically the farthest from the grounding point and connect it to the other terminal of the current supply Attach a voltmeter to the two conductive components near the current leads Then, apply a current of 2.5 times ± 10% of the module's maximum over-current protection rating for at least 2 minutes, and measure the applied current along with the resulting voltage drop Afterward, reduce the current to zero and repeat the test on an additional frame component.
The resistance between the selected exposed conductive component and each other conductive component of the module shall be less than 0,1 Ω.
Impulse voltage test MST 14
The article assesses the solid insulation's ability to endure atmospheric over-voltages and those caused by the switching of low-voltage equipment.
NOTE If the PV module is not going to be sold without frame, the impulse voltage test should be done with the module framed
The apparatus is as follows: a) Impulse voltage generator b) Oscilloscope
To ensure test reproducibility, the test is performed at room temperature and relative humidity below 75% The procedure involves covering the entire module with copper foil, which is then connected to the negative terminal of the impulse voltage generator Additionally, the shorted output terminals of the module are connected to the positive terminal of the generator.
1) Thickness copper 0,03 mm to 0,05 mm
2) Conducting glue (conductivity resistance